![Structure of a polymer chain](images/grAndSq.jpg) |
Shown is the radial distribution function and the structure factor of a
polymer chain in a melt. At short distances ( large q) the excluded volume interactions
are important. The exponent is thus that of a self-avoiding random walk (0,59..). At large
distances the polymer shows a random walk behaviour. The cross-over from self-avoiding
random walk to random walk behaviour gives the screening length. |